Sifting or screening apparatus.



No. 841,959. PATENTED JAN. 22, 1907.

J. GBNTRUP.

'SIFTING 0R SCREENING APPARATUS.

APPLICATION FILED JUNE 5. 1905.

I r I lT/YED 5 Him THE-NORRIS PETERS :0 WASHINGTON, n. :4

UNITED STATES PATENT O FICE.

SIFTING OR SCREENING APPARATUS.

Specification of Letters Patent.

Patented Jan. 22, 1907.

Application filed Juno 1905. Serial No. 263.855.

a To an 'whom it may concern;

Be it known that I, Josnr GENTRUP, a subject of the King of Prussia,German Emperor, and a resident of Brochterbeck, near Munster, Germany,(whosepost-ofl ice address is Brochterbeck, near lVliinster, Prussia,

German Empire,) have invented Improvements Relating to Sifting orScreening Apparatus, of which the following is a specification.

' This invention has for its object a stationarythat is to say, anunoperated-funnel or conical gravity-sieve, in which, while dispensinwith any parts for producing centrifuga force or shaking, the momentumof the falling material alone is utilized in such a manner that allmovable parts and the wear inherentin the same are avoided, while thesifting or bolting is effected more expeditiously and more efficiently.

The means employed for this purpose consist of a principal funnel-sievewith an angle of inclination such that a spontaneous rolling down of thematerial on the sieve-surface is insured without the provision ofappliances for moving or shaking this surface, of a distributing memberfixed above the funnelsieve and likewise conical in form, which member,acting as a sieve and presenting a correctly-calculated angle ofinclination, delivers the material uniformly spread out and broken upinto an outer annular channel supplying the funnel-sieve, and,further,-comprise the provision of a receiving-hopper beneath thedistributing-cone for the reception of the material of the first siftingoperation. which does not reach the funnel-sieve, and, finally,appropriate conveying and delivering devices.

A constructional form of sifting apparatus designed in accordance withthe novel ideas set forth above is illustrated in the acc0 m.

panying drawing, its essential parts being shown in axial verticalsection.

In this apparatus, a is the principal sieve, which is here termed thefunnel-sieve, and throughout this description funnel and hopper areinvariably used to designate a conical body with its apex lowermost,while by cone should be understood a body which is similargeometrically, but which is arranged with its apex uppermost.

Thefunnel-sieve a is constructed with an angle of descent appropriatefor the frictional or sliding angle of the material to be treated,

and the perforated sheet metal or other material used for the purposeshould, of course, be

selected with due regard tothe class of material that it is intended totreat in the apparatus.-

The funnel-sieve'a is connected with a receiving-hopper b, and thisconnection may be conveniently effected at the upper part by means oflugs provided on the edge andlikewise by appropriately connecting thedischarge-conduits f f and g g.

Upon the upper edge-of the funnel-sieve is fixed the distributing-cone cby means of lugs, as shown, and this body, which exerts a very importanteffect at the beginning of the operation upon the material to be sifted,should of course be constructed as regards its angle of inclination soas to correspond Withthe funnel-sieve, and it should be perforated in amanner suited to the material to be treated. Surrounding the base of thedistributingcone is an annular channel, the outer wall of which isformed by the upper part of the funnel-sieve, through which channel thematerial from the distributing-cone passes to the funnel-sieve.

The receiving-hopper d is fitted to the lower edge of thedistributing-cone c, this hopper directly catching any material fallingthrough the cone 0 during the charging of the funnel-sieve a, therebyfreeing it from attack by the entire mass of material, thus renderingthe treatment of this latter not onlyv more speedy, but more easy,because, as is well-known, not only does the freedom with whichparticles roll increase with their size, but, further, a fine or sandymass will retain coarse particles embedded in it, thereby making it moredifficult for these particles to roll and accordingly rendering it moretroublesome to sift them.

The material to be treated is conducted to the distributing-cone c,which is preferably constructed with a sharp apex through an annularpassage in the known manner, and usually as directly as possible fromconveyerchannels or similartransporting appliances discharging into afeed-hopper i, which is a propriately connected with the frame of t eentire apparatus. This hopper i conducts the material onto thedistributing-cone 0 through a tube h, which may advantageously betelescopic in construction in the known manner. It is likewisepreferably provided with adjusting means, so that the annular slitthrough which the material passes onto the apex of the distributing-cone0 may be exactly-regulated in accordance with the nature of the materialtreated and the rate at which it is supplied to the apparatus.

While the fine material which has passed through the funnel-sieve aproceeds over the receiving hopper b and falls into the discharge-pipe gg, the coarser material, which is unable to pass through in this manner,rolls down a and passes out laterally through f f. The tube 6, fitted tothe receivin hopper d of the cone 0, also passes throug this latter, andin this'manner, notwithstanding the fact that the sifting operationtakes place in two phases, so as to speak, the fine and coarse materialobtained at different places is discharged through two outlets only.

The cooperation of a funnel-sieve in accordance with the foregoingdescription, which gives full play to the rolling or falling force ofthe material treated with a stationary distributing-cone, and likewiseappropriate receiving and discharge members, produces a total operativeeffect in the novel undriven unoperated sifting apparatus such that thislatter, even though of small dimensions, isable to treat considerablequantities even of more or less agglomerated material with greatrapidity and with the formation of but little dust, while the liabilityof the sieves to become stopped and the necessity for scraping the sameis reduced to a minimum.

What I claim, and desire to secure by Letters Patent of the UnitedStates, is

1. In a sifting apparatus the combination coarse material, substantiallyas and for the purpose set forth.

2. In a sifting apparatus thecombination with a feed-hopper, astationary perforated distributing-cone, receiving-hopper beneath thedistributing-cone,; stationary funnelshaped sieve, annular channelbetween the base of the distributing-cone and the upper part of thefunnel-shaped sieve, receivinghopper around said funnel-sieve anddischarge-conduits for the fine and coarse material, substantially asand for the purpose set forth. I

In testimony whereof I have hereunto set my hand in presence of twosubscribing witnesses.

JOSEF GENTRUP. Witnesses:

LUCAS SON'KER, AUGUST SIEGFRIED DOOAN.

